Manufacture of condensation products



Patented July 19, 1932 though it is distinctly UNITED S ATES PATENToFFIcEH aueusrn v rcroa karma, or warm GARDEN crr'r, arrenan'nmnuracruan or conmms urrou rnonuc'rs 1T0 Drawing. Application filedDecember 8, 1898, Serial I0. 418,291, and In tireatBritaln November Thisinvention relates to the manufacture of condensation'products derivedfrom the reaction of urea and an aldehyde.

When urea and formaldehyde or its solid polymers are condensed insolution without the aid of accelerating agents, the resulting producttends to become unstable and to precipitate any uncombined aldehyde.When, on the other hand, the condensation occurs in anhydrous orsemi-anhydrous conditions, advantageous m many respects so to promotethe reaction in the partial or total absence of water, yet uponsubsequent dilution, for example when endeavoring to obtaina solutionwhich may be used as an impregnate, the product will befound not topossess absolute tran arency.

- I have now found that sation reaction is carried outunder'substantially dry conditions, that is in the absence of freeliquid as a solvent to romote the reaction, but in the presence smallamounts tion of saturated steam,

, of the desired consistenc trolling the speed of t e reaction and in ofacidic bodies and alkaline substances acting as catalysts, it ispossible to produce clear, transparent, viscous condensation productsfrom urea and solid polymers of formaldehyde. which remain stable and donot tend to solidify when kept over an indefinite period, nor to becometurbid on standing or when further diluted.

According to this invention, substances and the alkaline catalyst arefirst mixed in a dry state, being preferably further mixed, moistenedand heatedby the introducbeing added last, in order to an to aid inconrendermg the initial condensation roduct stable. The acidic andalkaline b0 ies acting as catalysts form for example less thanon%Eerjcent of the total reacting masses.

process may be carried out as indicated in the accompanyin examples.Ewample 1.-160l s. of. paraformaldehyde and 1 ozs. of an alkaline salt,such as sodium hydroxide, or 3 ozs. ofsodium bicarbonate or 4 ozs. ofsodium carbonate, or

the molecular equivalent of another basic salt,-

are intimately mixed in a dry state at a tour reaction w an thecondenthe reacting a and the acidic body 'eld a product perature of C. ajacketed and enclosed I liminary reaction takes place with the roductionof mono-methylol'urea or di-met ylol urea or a mixture of the two,according to the exact temperature'and'pressure. condi vessel with 120lbs. of urea. 1 A preof 2 lbs. of mono-sodium phosphate or its molecularequivalent .in mono-potassium or mono-ammonium phosphate. Thewholemixing is then allowed to react and main- 'tainedat atemperatureofabout 120 C. for

20 minute's,'the mixture being agitated dur ing the process by stirrinfgcontinued introduction '0 saturated steam.

Ewample 21-160 lbs. of paraformaldehyde are intimately admixed, as inExample 1, with 120 lbs. of urea. Meanwhile, a concentrated solution of2 lbs. of mono-sodium phosphate,

and 1 lb. of di-sodium phosphate is made, and 15 minutes after the ureaand paraformaldehyde have been mixed in a dry state, this solution isadded, the temperature being increased and saturated the vessel.

ly short space of time; it it is clear, viscous, remains stable underdecrease temperature. The product may be solidified by evaporation,

oes not coagulate,

blades and by the 1 The product obtained is reduced in a fair and transarent, and it steam injected into preferably in vacuo, and, if thenground into a fine powder, parent, insoluble final reaction product bythe application of reaction may be conducted under elevated orintroducing the catalytic agents ma 'be removed by eva crating in vacuo,if high concentration is product is sufiiciently evaporated.

it may be formed into a transpressure and/or heat. The

decreased pressure,-and the water added when esired, until thecondensation H I have found that, b combinin urea and paraformaldeh dein t e manner erein described, the pre iminary reaction between the twosubstances greatly reduces the time ofthe total c0ndensat1on."','

in large scale manufacture,

A further advantage of my rocess is that the introduction of saturatesteam overcomes the mass-attraction when dealin with I large quantities,and causes a fine division or sphtting up of the materials, thusenabling minutes, eliminating the tediouslong boiling I under reflux aswlth urea formaldehyde prodtioned above may aldehyde condensation 1ncombinin with mixture, adding a small percentage of ac d phosphate, andmaintaining the heat of 'urea and a soli ucts.

This invention is not restricted to the particular temperatures,pressures, conditions and quantities described in the examples givand itis understood that variations in either direction may be made in one ormore or any or all of these factors.

Salts, acids or bases other than those manbe used to accelerate, retardor otherwise catalytically influence the process of manufacture. By theexpression alkaline substance or alkaline catalyst, I

mean any caustic alkali; by the ex ression acidlc body or acidiccatalyst, -mean any acid-reacting salt, such as the acid phosphatesmentioned, to the exclusion of sodium bicarbonate and like acid salts ofstrong v bases and weak acids.

WhatI claim is v v 1. A process for the manufacture of urea-aldehydecondensation products in stable form, consisting in preparing a drymixture of a solid polymer of formaldehyde and urea with a very smallpercentage of an alkaline substance, injecting steam into the mixture,adding a small percents. e of an acid phosphate, and maintaining t eheat while stirring the mixture. I p

' 2. A process for the manufacture of ureaaldehyde condensation productsin stable form, consisting in combinin urea in a dry state with a solidpolymer 0 formaldehyde in presence of an alkaline catalyst to a methylolurea, injecting steam into the an while stirring the mixture. 7 v

3. A process for the manufacture ofureaaldehyde condensation products instable form, consisting in preparing a jecting steam into the mixture,adding a small percentage of an acidic catalyst, and main- .taining theheat while agitating the mixture for some minutes. e

4. A process for manufacturing urearoducts, consisting urea in a;ry'state with parain presence of a very sma 'n ecting tteam formaldehy eadding a small percentage of a caustic alkali, agitation of the mixture,

completed within 40 I percentage of an acid phosphate, maintaining theheat while stirrmg the mixture, an solidifying the product by'evaporation.

5; A process for manufacturing ureaaldehyde condensation roducts,consisting in combining urea in a ry'state with paraformaldehyde inpresence of a very, small percentage of a caustic alkali, injectingsteam with agitation of the mixture, percentage of an acid phosphate,maintaining the heat while stirring the mixture, solidifying the productby evaporation, grinding the'solidified product, and converting it intothe final reaction productby application of eat.

6. A process for manufacturing ureaaldehyde condensation products,consisting adding a small in combining urea and paraformaldehyde by Intestimony whereof, I have aliixed my signature.

AUGUSTE VICTOR KELLER.

produce dry'mixture polymer of formalde-q hyde in presence of analkaline catalyst, ina

